Measuring device

Abstract

Provided is a measurement device provided with a small and lightweight movable body. A measuring device (1) is provided with: a movable part (11) having a mirror (113); a movable part (12) having a light emission point (121), light incidence points (122a, 122b), and an optical system; a drive mechanism (13) for adjusting the position of the movable part (12); a control unit (14) that controls the drive mechanism (13); and at least one optical fiber (16). Light emitted from the light emission point (121) is irradiated to the mirror (113) via the optical system, and reflected light reflected from the mirror (113) is incident to the light incidence points (122a, 122b). The control unit (14) adjusts the position of the movable unit (12) by controlling the drive mechanism (13) on the basis of the intensity of the reflected light incident on the light incident points (122a, 122b). The light exit point (121) or the light incidence point (122a or 122b) is an end portion (161) of the at least one optical fiber (16).

Description

Technical Field

[0001] The present disclosure relates to a measuring device. Background Art

[0002] A contact three-dimensional shape measuring instrument is used for highly precisely measuring the shape of a lens or the like. Patent Document 1 discloses the configuration of an optical probe for a contact three-dimensional shape measuring instrument.

[0003] (Prior Art Document)

[0004] (Patent Document)

[0005] Patent Document 1: Japanese Patent No. 3000819 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] An object of the present disclosure is to provide a measuring device including a small and lightweight movable body.

[0008] Means for Solving the Problems

[0009] A measuring device according to one aspect of the present disclosure includes: a first movable body having a reflector; a second movable body having a light emission point, a light incidence point, and an optical system; a drive mechanism that adjusts the position of the second movable body; a control unit that controls the drive mechanism; and at least one optical fiber. Light emitted from the light emission point is irradiated onto the reflector via the optical system, and reflected light reflected from the reflector is incident on the light incidence point. The control unit controls the drive mechanism based on the intensity of the reflected light incident on the light incidence point, and thereby adjusts the position of the second movable body. The light emission point or the light incidence point is an end portion of the at least one optical fiber.

[0010] Effects of the Invention

[0011] According to the present disclosure, it is possible to provide a measuring device including a small and lightweight movable body. Brief Description of the Drawings

[0012] Figure 1 It is a diagram showing a schematic configuration of the measuring device according to Embodiment 1.

[0013] Figure 2 It is a diagram showing a schematic configuration of the measuring device according to Embodiment 2.

[0014] Figure 3 It is a diagram showing a schematic configuration of the measuring device according to Embodiment 3.

[0015] Figure 4This is a diagram showing the schematic configuration of the measuring device according to Embodiment 4.

[0016] Figure 5 This is a diagram showing the concept of an optical fiber bundle.

[0017] Figure 6 This is a diagram showing the schematic configuration of a conventional three-dimensional shape measuring instrument.

[0018] Explanation of reference numerals

[0019] 1, 2, 3, 4 Measuring device

[0020] 10 Probe

[0021] 11, 12 Movable part

[0022] 13 Driving mechanism

[0023] 14 Control unit

[0024] 15 Spring

[0025] 16, 17, 18 Optical fiber

[0026] 19 Optical fiber bundle

[0027] 19A, 19B, 19C, 19D, 19E, 19F, 19G Core

[0028] 20 Light source unit

[0029] 21 Laser element

[0030] 22 Optical system

[0031] 31a, 31b Photodetector

[0032] 40 Interferometer

[0033] 50 Air supply unit

[0034] 111 Probe head

[0035] 112 Sliding part

[0036] 113 Mirror

[0037] 120a Guide mechanism

[0038] 120b Probe housing

[0039] 121 Light exit point

[0040] 122, 122a, 122b Light incident point

[0041] 123 Collimating lens

[0042] 124 and 129 optical elements

[0043] 125 and 126 condenser lenses

[0044] 127 beam splitter

[0045] 128a and 128b light-shielding members

[0046] 161, 162, 171, 172, 181, 182, 191 ends. Detailed implementation mode

[0047] (Summary of the present disclosure)

[0048] The inventors of the present invention have found the following problems with the optical probe used in the three-dimensional shape measuring instrument disclosed in Patent Document 1. Hereinafter, with reference to the configuration of the optical probe disclosed in Patent Document 1, the problems of the conventional optical probe will be described.

[0049] Figure 6 It is a schematic configuration diagram showing a conventional three-dimensional shape measuring instrument. As Figure 6 shown, the three-dimensional shape measuring instrument 1x includes an optical probe 10x. The optical probe 10x is composed of two elements, a movable part 11x and a movable part 12x.

[0050] The movable part 11x moves up and down along the shape of the measurement object (not shown). The three-dimensional shape measuring instrument 1x irradiates light Lx (shown by a dotted line in Figure 6 ) from the outside of the optical probe 10x to the movable part 11x, and determines the position of the movable part 11x based on the reflected light thereof. Accordingly, the three-dimensional shape measuring instrument 1x obtains the shape information of the measurement object.

[0051] The movable part 12x has a function of restricting the movement of the movable part 11x in the vertical direction. And, the movable part 11x and the movable part 12x are connected by a spring 15x. In order to keep the contact strength between the movable part 12x and the measurement object within a certain range, it is necessary to keep the relative position between the movable part 11x and the movable part 12x within a certain range.

[0052] And in the configuration of Patent Document 1, the objective lens 125x is placed on the movable part 12x. The objective lens 125x condenses the light incident from the outside of the optical probe 10x onto the mirror 113x on the movable part 11x. The objective lens 125x emits the reflected light reflected by the mirror 113x to a laser length measuring instrument (not shown) outside the optical probe 10x. In order for the reflected light to return to the laser length measuring instrument, it is necessary to position the mirror 113x of the movable part 11x near the focal position of the objective lens 125x of the movable part 12x. From this point of view, in the optical probe 10x, it is necessary to keep the relative position between the movable part 11x and the movable part 12x within a certain range.

[0053] The movable part 12x includes a semiconductor laser 21x, a photodetector 31ax, and 31bx, and is used as a unit for measuring the relative position between the movable part 11x and the movable part 12x. The reason why the movable part 12x includes two photodetectors 31ax and 31bx is that the signal intensities of the detected signals have different dependencies on the relative position between the movable part 11x and the movable part 12x. With this configuration, when deviating from the desired relative position, in order to reach the desired relative position, it is possible to calculate in which direction and by how much the movable part 12x needs to be moved.

[0054] As Figure 6 shown, the contact three-dimensional shape measuring instrument includes a driving unit 13x and a relative position measuring unit 14x.

[0055] The relative position measuring unit 14x calculates the relative position between the movable part 11x and the movable part 12x based on the outputs of the photodetectors 31ax and 31bx respectively. The driving unit 13x adjusts the relative position between the movable part 11x and the movable part 12x by changing the position of the movable part 12x while keeping the relative position unchanged.

[0056] In order to measure the three-dimensional shape of the measurement object, the three-dimensional shape measuring instrument changes the relative position in the horizontal direction between the optical probe 10x and the measurement object. In this case, the movable part 11x changes its position in the vertical direction according to the shape of the measurement object. Whenever the relative position in the horizontal direction is changed, in order to keep the relative position between the movable part 11x and the movable part 12x unchanged, it is necessary to measure the relative position and change the position of the movable part 12x.

[0057] However, if the position change speed of the movable part 12x is slow, it will restrict the shape measurement. And when the position change cannot be carried out immediately, the relative position between the movable part 11x and the movable part 12x will exceed the appropriate range. In this case, there will be a problem that the movable part 11x presses the measurement object excessively, or there will be a problem that the movable part 11x leaves the measurement object and normal measurement cannot be performed.

[0058] The weight of the movable part 12x affects the position change speed of the movable part 12x. In order to increase the position change speed, it is necessary to make the movable part 12x as light as possible. And in order to suppress the physical interference between the measurement object and the movable part 12x, it is necessary to make the movable part 12x as small as possible.

[0059] Therefore, an object of the present disclosure is to provide a measuring device having a small and lightweight movable body.

[0060] The measuring device according to the first aspect of the present disclosure includes: a first movable body having a reflector; a second movable body having a light emitting point, a light incident point, and an optical system; a drive mechanism for adjusting the position of the second movable body; a control unit for controlling the drive mechanism; and at least one optical fiber. The light emitted from the light emitting point is irradiated onto the reflector via the optical system, and the reflected light reflected from the reflector is incident on the light incident point. The control unit controls the drive mechanism according to the intensity of the reflected light incident on the light incident point, thereby adjusting the position of the second movable body. The light emitting point or the light incident point is the end of the at least one optical fiber.

[0061] Accordingly, since the light emitting point or the light incident point is the end of at least one optical fiber, the second movable body can be miniaturized and lightened. This is because the size of the end of the optical fiber is generally smaller than that of a semiconductor laser or a photodetector, which helps to miniaturize and lighten the second movable body. Also, in the case where components such as a semiconductor laser or a photodetector are provided, a power supply line for operating the component and a signal line for extracting the signal output from the component are required. In contrast, by using an optical fiber, there is no need to provide a power supply line and a signal line, thus reducing the number of cables connected to the second movable body. In this regard, the second movable body can also be miniaturized and lightened.

[0062] The measuring device according to the second aspect of the present disclosure is the measuring device according to the first aspect, and when measuring an object, the first movable body is in contact with the object.

[0063] When a contact-type measuring device measures a measurement object, the distance between the second movable body and the measurement object also becomes closer. Therefore, by miniaturizing the second movable body, it is easier to avoid contact between the second movable body and the measurement object.

[0064] The measuring device according to the third aspect of the present disclosure is the measuring device according to the first aspect or the second aspect, and includes an elastic body that connects the first movable body and the second movable body.

[0065] Accordingly, the relative position between the first movable body and the second movable body can be easily maintained within a certain range. Also, in the case of a contact-type measuring device, the elastic body can be used to apply a pressing force of the first movable body on the measurement object. In this way, it is possible to prevent the first movable body from leaving the measurement object and improve the measurement accuracy.

[0066] The measuring device according to the fourth aspect of the present disclosure is the measuring device according to any one of the first to third aspects. The at least one optical fiber includes a first optical fiber, and the light-emitting point is the first end of the first optical fiber. The second movable body has: a beam splitter that separates the reflected light into a first reflected light and a second reflected light; a first light-shielding member having a first pinhole for the first reflected light to enter; and a second light-shielding member having a second pinhole for the second reflected light to enter. The second movable body has a plurality of the light-incident points, and each of the first pinhole and the second pinhole is the light-incident point.

[0067] Accordingly, it is not necessary to provide a light source such as a laser element that also becomes a heat source in the second movable body. Thus, since the temperature rise of the second movable body can be suppressed, the change in the refractive index of the air inside the second movable body can also be suppressed. Therefore, the change in the optical path of the light used in the measurement of the measurement object can be suppressed, and thus the reduction in the measurement accuracy can be suppressed.

[0068] The measuring device according to the fifth aspect of the present disclosure is the measuring device according to any one of the first to third aspects. The second movable body has: a laser element including the light-emitting point; and a beam splitter that separates the reflected light into a first reflected light and a second reflected light. The at least one optical fiber includes: a second optical fiber having a second end for the first reflected light to enter; and a third optical fiber having a third end for the second reflected light to enter. The second movable body has a plurality of the light-incident points, and each of the second end and the third end is the light-incident point.

[0069] Accordingly, since it is possible to connect two optical fibers to the second movable body instead of providing a member having a pinhole as the light-incident point and a photodetector, miniaturization and weight reduction of the second movable body can be achieved.

[0070] The measuring device according to the sixth aspect of the present disclosure is the measuring device according to any one of the first to third aspects. The second movable body has a beam splitter that separates the reflected light into a first reflected light and a second reflected light. The at least one optical fiber includes: a first optical fiber; a second optical fiber having a second end for the first reflected light to enter; and a third optical fiber having a third end for the second reflected light to enter. The light-emitting point is the first end of the first optical fiber. The second movable body has a plurality of the light-incident points, and each of the second end and the third end is the light-incident point.

[0071] Accordingly, miniaturization and weight reduction of the second movable body can be achieved. Moreover, deterioration of the measurement accuracy due to heat generation can be suppressed.

[0072] The measuring device according to the seventh aspect of the present disclosure is the measuring device according to any one of the first to sixth aspects, the at least one optical fiber includes a multi-core optical fiber, the multi-core optical fiber includes a plurality of cores, the second movable body has a plurality of the light incident points, and end portions of the respective plurality of cores are the light incident points.

[0073] Accordingly, since the number of optical fibers fixed to the second movable body can be reduced, miniaturization and weight reduction of the second movable body can be achieved.

[0074] The measuring device according to the eighth aspect of the present disclosure is the measuring device according to any one of the first to seventh aspects, and the at least one optical fiber is a single-mode optical fiber.

[0075] Accordingly, since the light incident point or the light exit point can be made smaller, further miniaturization of the second movable body can be achieved.

[0076] The measuring device according to the ninth aspect of the present disclosure is the measuring device according to any one of the first to seventh aspects, and the at least one optical fiber is a multi-mode optical fiber.

[0077] Accordingly, light easily enters the optical fiber.

[0078] The measuring device according to the tenth aspect of the present disclosure is the measuring device according to any one of the first to ninth aspects, and the optical system includes a gradient index lens fixed to an end portion of the at least one optical fiber.

[0079] Accordingly, since the optical system can be miniaturized and light-weighted, the second movable body can be miniaturized and light-weighted.

[0080] The measuring device according to the eleventh aspect of the present disclosure is the measuring device according to the first or tenth aspect, the at least one optical fiber includes a multi-core optical fiber, the multi-core optical fiber includes a plurality of cores, and an end portion of one of the plurality of cores is the light incident point and is the light exit point.

[0081] Accordingly, the optical fiber connected to the second movable body can be constituted by only one multi-core optical fiber. Therefore, it contributes to miniaturization of the second movable body.

[0082] The measuring device according to the twelfth aspect of the present disclosure is the measuring device according to the fourth or sixth aspect, the measuring device includes a laser element, light emitted from the laser element enters from an end portion of the first optical fiber on a side opposite to the first end portion, and is transmitted in the first optical fiber and exits from the first end portion.

[0083] Accordingly, since the laser element can be separately provided from the second movable body, it is easy to replace the laser element when it deteriorates. It is possible to suppress a decrease in the measurement accuracy of the measurement object due to heat generated when the laser element emits light.

[0084] The measuring device according to the thirteenth aspect of the present disclosure is the measuring device according to any one of the first aspect to the twelfth aspect, and the measuring device includes a light intensity measuring unit that measures the intensity of reflected light incident on the light incident point.

[0085] Accordingly, since the light intensity measuring unit can be separately provided from the second movable body, it is easy to replace the light intensity measuring unit when it deteriorates.

[0086] Hereinafter, embodiments of the present disclosure will be specifically described with reference to the drawings.

[0087] In addition, the embodiments to be described below are all general or specific examples. The numerical values, shapes, materials, constituent elements, arrangement positions and connection methods of the constituent elements, steps, order of steps, etc. shown in the following embodiments are all examples, and the gist thereof is not to limit the present disclosure. And, among the constituent elements of the following embodiments, the constituent elements not described in the independent claims will be described as optional constituent elements.

[0088] Moreover, each drawing is a schematic diagram for conceptual explanation only, and is not the actual size, shape, etc. Therefore, for example, the scales in each drawing do not have to be the same. And the same reference numerals are given to substantially the same components in each drawing, and repeated explanations are omitted or simplified.

[0089] In this specification, the light exit point is the portion where light exits into the second movable body and is a portion having a predetermined area. For example, the light exit point is the end of an optical fiber or the light exit surface of a light emitting element. The light incident point is the portion where light propagating inside the second movable body enters the light detector and is a portion having a predetermined area. For example, the light incident point is the end of an optical fiber or a pinhole.

[0090] In this specification, the "vertical direction" means the direction in which the relative position of the first movable body and the second movable body can change. Specifically, the direction parallel to the axis of the probe of the first movable body is the vertical direction. Along the axis of the probe, the tip direction is the "downward direction", and the opposite direction is the "upward direction". The tip of the probe contacts the measurement object.

[0091] In this specification, ordinal numbers such as "first" and "second" do not mean the number or order of constituent elements, etc. without special limitations, but are used for the purpose of distinguishing to avoid confusion of the same kind of constituent elements.

[0092] (Embodiment 1)

[0093] First, the measuring device according to Embodiment 1 will be described. The measuring device according to this embodiment is configured such that, instead of providing a laser light source in the movable part, the end of the optical fiber connected to the light source is connected to the movable part.

[0094] The following will use Figure 1 to describe the specific configuration of the measuring device according to this embodiment. Figure 1 FIG. is a diagram showing a schematic configuration of the measuring device according to this embodiment.

[0095] The measuring device 1 according to this embodiment is a three-dimensional shape measuring instrument. Specifically, the measuring device 1 measures the surface shape of a measurement object (not shown). As Figure 1 shown, the measuring device 1 includes a probe 10, a drive mechanism 13, a control unit 14, a spring 15, and an optical fiber 16. And the measuring device 1 includes a light source unit 20, photodetectors 31a and 31b, an interferometer 40, and an air supply unit 50.

[0096] [Probe]

[0097] The probe 10 includes a movable part 11 and a movable part 12. The movable part 11 is an example of a first movable body having a reflector. The movable part 12 is an example of a second movable body having a light emission point, a light incident point, and an optical system.

[0098] The movable part 11 includes a probe tip 111, a sliding part 112, and a mirror 113. The probe tip 111 is fixed to the sliding part 112. When measuring the measurement object, the tip of the probe tip 111 contacts the measurement object. When the probe tip 111 contacts the measurement object, the movable part 11 will change its position in the vertical direction according to the shape of the measurement object. The sliding part 112 restricts the movement of the movable part 11 in the vertical direction. The mirror 113 is an example of the reflector provided in the first movable body. The mutual positional relationship among the probe tip 111, the sliding part 112, and the mirror 113 is fixed.

[0099] The movable part 12 includes a guiding mechanism 120a and a probe housing 120b. The relative positional relationship between the guiding mechanism 120a and the probe housing 120b is fixed. In the present embodiment, the movable part 12 has a light emission point 121 and light incident points 122a and 122b. The light emission point 121 is the end 161 of the optical fiber 16. The light incident point 122a is the first pinhole of the light shielding member 128a. The light incident point 122b is the second pinhole of the light shielding member 128b. Further, light detectors 31a and 31b are provided on the movable part 12. The movable part 12 has an optical system fixed to the probe housing 120b.

[0100] The optical system includes a collimating lens 123, a condenser lens 125 on the side of the mirror 113, and a condenser lens 126 on the side of the light detectors 31a and 31b. The optical system further includes optical elements 124 and 129 and a beam splitter 127.

[0101] The collimating lens 123 converts the light emitted from the light emission point 121 into light that is close to parallel light (hereinafter referred to as parallel light). Light that is close to parallel light means that the light incident on the collimating lens 123, that is, in the present embodiment, light with a divergence angle smaller than the light emitted from the end 161 of the optical fiber 16.

[0102] The condenser lens 125 condenses the incident light near the mirror 113. For example, the condenser lens 125 condenses the parallel light that passes through the collimating lens 123 and the optical element 124 and is reflected by the optical element 129 near the mirror 113. Further, the condenser lens 125 converts the reflected light reflected by the mirror 113 into parallel light and makes it incident on the condenser lens 126 via the optical elements 129 and 124. In the present embodiment, the condenser lens 125 condenses the measurement light L for measuring the object to be measured near the mirror 113. The condenser lens 125 converts the reflected light of the light L that passes through the mirror 113 into parallel light and makes it incident on the interferometer 40 via the optical element 129.

[0103] The condenser lens 126 condenses the incident light and makes it incident on the light incident points 122a and 122b.

[0104] The optical element 124 separates the light from the end 161 of the optical fiber 16, that is, the light emission point 121, toward the condenser lens 125, and the light from the condenser lens 125 toward the condenser lens 126 (the reflected light that passes through the mirror 113). The optical element 124 is, for example, a polarization beam splitter. A polarization beam splitter is an optical element having a dielectric multilayer film, which reflects the light component having an electric field parallel to the dielectric multilayer film and transmits the light component having an electric field orthogonal thereto.

[0105] For example, the light emerging from the collimating lens 123 is set to be a component that passes through the dielectric multilayer film. Accordingly, the light emerging from the collimating lens 123 can pass through the optical element 124 and be directed toward the condenser lens 125 side.

[0106] Moreover, by placing a λ / 4 wave plate on the optical path between the polarization beam splitter, i.e., the optical element 124, and the condenser lens 125, it is possible to pass through the λ / 4 wave plate both when going from the optical element 124 toward the condenser lens 125 and when going from the condenser lens 125 toward the optical element 124. By appropriately selecting the angle of the λ / 4 wave plate, it is possible to rotate the electric field direction of the light going from the optical element 124 toward the condenser lens 125 side and the electric field direction of the light emerging from the condenser lens 125 side and incident on the optical element 124 by 90 degrees. In this way, by rotating the electric field direction, the optical element 124 can direct the light from the condenser lens 125 side toward the condenser lens 126 side. It is also possible to place an element for controlling the electric field direction, such as a polarizer or a λ / 2 wave plate, between the collimating lens 123 and the optical element 124. Alternatively, it is possible to control the direction of the electric field of the light emerging from the collimating lens 123 by regarding the optical fiber 16 as a polarization-maintaining optical fiber and regarding the direction of its end portion 161 as a specific direction.

[0107] The optical element 124 can also be an element other than a polarization beam splitter. For example, a polarization-insensitive beam splitter can be used as the optical element 124. For example, when the optical element 124 is a beam splitter with a splitting ratio of 50:50, 1 / 2 of the light emerging from the collimating lens 123 and incident on the optical element 124 goes toward the condenser lens 125 side, and 1 / 2 of the light emerging from the condenser lens 125 and incident on the optical element 124 goes toward the condenser lens 126 side. That is, approximately 1 / 4 of the light passing through the collimating lens 123 goes toward the condenser lens 126 side. Compared with the configuration using a polarization beam splitter, although there is a loss of light intensity, this configuration can simplify the structure. In addition, the splitting ratio of the beam splitter is not limited to 50:50, but can be other splitting ratios such as 10:90 or 30:70.

[0108] The optical element 129 is an optical element for superimposing the optical path of the measurement light L used in the interferometer 40 and the optical path of the light for measuring the relative positions of the movable parts 11 and 12 and for incident on the mirror 113. And the optical element 129 separates the reflected light reflected from the mirror 113 and passing through the condenser lens 125 into the reflected light for incident on the interferometer 40 and the reflected light for measuring the relative positions of the movable parts 11 and 12. Although the optical element 129 is, for example, a dichroic mirror, it can also be a semi-transmissive semi-reflective mirror, a beam splitter cube, a cube polarization beam splitter, etc.

[0109] For example, as long as the wavelength of the light L used in the interferometer 40 is different from the wavelength of the light used to measure the relative positions of the movable parts 11 and 12, the optical paths of the two lights can be made to coincide or almost completely separated by an optical element having wavelength dependence such as a dichroic mirror. In Figure 1 the configuration of, a dichroic mirror that transmits the light L used in the interferometer 40 and reflects the light used to measure the relative positions of the movable parts 11 and 12 is employed as the optical element 129.

[0110] Alternatively, as long as the polarization of the light L used in the interferometer 40 is different from the polarization of the light used to measure the relative positions of the movable parts 11 and 12, the optical paths of the two lights can be made to coincide or almost completely separated by an optical element having polarization dependence such as a cube polarization beam splitter. And it can also be that, in the case of adopting an unpolarized beam splitter and having a configuration in which the optical paths of the light used in the interferometer 40 and the light used to measure the relative positions of the movable parts 11 and 12 are superimposed, an optical element that transmits one light and blocks the other light can be arranged on the optical path where the two lights are to be separated. For example, a notch filter, a band-pass filter, a long-pass filter, or a short-pass filter, etc. can be arranged.

[0111] The beam splitter 127 separates the light that comes from the condenser lens 125 and passes through the condenser lens 126 into two. Specifically, the beam splitter 127 separates the reflected light reflected from the mirror 113 into a first reflected light and a second reflected light. More specifically, the beam splitter 127 performs intensity splitting on the reflected light, and after splitting it into the first reflected light and the second reflected light, emits them in different directions. The ratio of the intensity splitting performed by the beam splitter 127 is, for example, 1:1, but is not limited thereto.

[0112] In the present embodiment, the optical system included in the movable part 12 may further include an optical element having refractive power in addition to the collimating lens 123 and the condenser lenses 125 and 126.

[0113] The movable part 12 has a light-shielding member 128a and a light-shielding member 128b. The light-shielding member 128a has a first pinhole located on the optical path of the first reflected light separated by the beam splitter 127, and the light-shielding member 128b has a second pinhole located on the optical path of the second reflected light. The first reflected light enters the first pinhole included in the light-shielding member 128a, that is, enters the light incident point 122a. The second reflected light enters the second pinhole included in the light-shielding member 128b, that is, enters the light incident point 122b. The distances from the principal point of the condenser lens 126 are different for the first pinhole as the light incident point 122a and the second pinhole as the light incident point 122b.

[0114] The relative position of the movable part 12 with respect to the movable part 11 is variable. The guide mechanism 120a of the movable part 12 restricts the movement of the movable part 11 in the vertical direction. An air supply part 50 is connected to the movable part 11. By the air supplied from the air supply part 50, the movement of the movable part 11 can be made smooth.

[0115] In the present embodiment, the movable part 11 and the movable part 12 are connected by a spring 15. The spring 15 is an example of the elastic body included in the measuring device 1. The spring 15 applies a force to the movable part 11 in the direction of pushing the movable part 11 against the measurement object (specifically, the downward direction). Accordingly, the contact between the probe 111 and the measurement object can be easily ensured, and the reliability of the measurement can be improved.

[0116] The measuring device 1 may include rubber, which is another example of the elastic body, instead of the spring 15. Also, the measuring device 1 may not include an elastic body. For example, the movable part 11 and the movable part 12 may be connected by a mechanism using a magnet or the like.

[0117] [Drive mechanism]

[0118] The drive mechanism 13 adjusts the position of the movable part 12. Specifically, the drive mechanism 13 receives a control signal from the control part 14 and changes the position of the movable part 12. The drive mechanism 13 is, for example, a linear motor or the like, but is not particularly limited as long as it can adjust the position of the movable part 12.

[0119] [Control part]

[0120] The control part 14 controls the drive mechanism 13. The control part 14 is a control signal generation part that generates a control signal output to the drive mechanism 13.

[0121] Specifically, the control part 14 adjusts the position of the movable part 12 by controlling the drive mechanism 13 according to the intensity of the reflected light incident on the light incident point. More specifically, the control part 14 calculates the relative position between the movable part 11 and the movable part 12 based on the output signals from the light detectors 31a and 31b. The control part 14 calculates the distance and direction in which the movable part 12 should move in order to keep the calculated relative position within a specified range. Then, the control part 14 sends a control signal to the drive mechanism 13, and this control signal is a signal for moving the movable part 12 by the calculated distance in the calculated direction. The method for calculating the relative position between the movable part 11 and the movable part 12 will be described later.

[0122] [Optical fiber]

[0123] The optical fiber 16 is an example of the first optical fiber and has an end part 161 and an end part 162.

[0124] The end portion 161 is an example of the first end portion and is the light emission point 121 of the movable portion 12. The end portion 161 is fixed directly or via other components to the probe housing 120b which is a component of the probe 10.

[0125] The end portion 162 is the end portion of the optical fiber 16 on the side opposite to the end portion 161. The end portion 162 is not fixed to the probe housing 120b. The end portion 162 is connected to the light source unit 20 and allows the light from the light source unit 20 to enter. The light emitted from the light source unit 20 enters from the end portion 162 of the optical fiber 16, is transmitted in the optical fiber 16, and then exits from the end portion 161.

[0126] In addition, the optical fiber 16 can be an optical fiber laser that emits light by itself. Alternatively, the optical fiber 16 can be an optical fiber having a wavelength conversion function such as a fluorescent optical fiber or a nonlinear optical fiber. In this case, the optical fiber 16 can emit only the wavelength-converted light, or can emit both the light before wavelength conversion and the wavelength-converted light. Thus, the optical fiber 16 can be integrated with the light source unit 20.

[0127] The optical fiber 16 can be a single-mode optical fiber or a multi-mode optical fiber. When the optical fiber 16 is a single-mode optical fiber, the light emission point 121 can be made smaller. By making the light emission point 121 smaller, an optical path with a small divergence angle can be produced by the optical system of the movable portion 12. Accordingly, it is easy to assemble a system in which the photodetectors 31a and 31b are sensitive to changes in the light quantity with respect to changes in the relative positions of the movable portion 11 and the movable portion 12. When the optical fiber 16 is a multi-mode optical fiber, it has the advantage that the light emitted from the light source unit 20 easily enters the end portion 162 of the optical fiber 16. Therefore, it is advantageous from the viewpoint of the signal-to-noise ratio.

[0128] [Light source unit]

[0129] The light source unit 20 emits light that can be detected by the photodetectors 31a and 31b. There is no special limitation on the wavelength of the light emitted from the light source unit 20, as long as the wavelength is different from the wavelength of the light used in the interferometer 40, the two can be easily separated by an optical element 129 such as a dichroic mirror.

[0130] As Figure 1 shown, the light source unit 20 includes a laser element 21 and an optical system 22. The laser element 21 is, for example, a semiconductor laser. Since the laser element 21 is a light source with a small light emission point, light easily enters the end portion 162 of the optical fiber 16. The optical system 22 is an optical element for allowing the light emitted from the laser element 21 to enter the end portion 162 of the optical fiber 16. In addition, the light source unit 20 may not include the optical system 22.

[0131] [Photodetector]

[0132] The optical detector 31a is an example of a light intensity measurement unit that measures the intensity of the first reflected light incident on the light incident point 122a. The optical detector 31b is an example of a light intensity measurement unit that measures the intensity of the second reflected light incident on the light incident point 122b. Each of the optical detectors 31a and 31b is, for example, a photoelectric conversion element such as a photodiode or a phototransistor.

[0133] The optical detector 31a detects the light passing through the first pinhole, that is, the first reflected light incident on the light incident point 122a. The optical detector 31a measures the intensity of the detected first reflected light and outputs a signal corresponding to the measured intensity to the control unit 14. The optical detector 31b detects the light passing through the second pinhole, that is, the second reflected light incident on the light incident point 122b. The optical detector 31b measures the intensity of the detected second reflected light and outputs a signal corresponding to the measured intensity to the control unit 14.

[0134] [Interferometer]

[0135] The interferometer 40 measures the position of the mirror 113 of the movable part 11 of the probe 10 using the light L. The mirror 113 is fixed at a position opposite to the probe tip 111. Since the position of the probe tip 111 in contact with the measurement object changes along the shape of the measurement object, the shape of the measurement object can be measured by measuring the position of the mirror 113.

[0136] The interferometer 40 serves as a light source for the light L used to measure, for example, a wavelength-stabilized He-Ne laser or a frequency-stabilized semiconductor laser. In addition, the probe 10 can independently include a mirror for reflecting the light L for the interferometer 40 and a mirror for reflecting the light for measuring the relative position between the movable part 11 and the movable part 12.

[0137] [Control method for the relative position between the movable part 11 and the movable part 12]

[0138] Next, a control method for the relative position between the movable part 11 and the movable part 12 will be described.

[0139] The light emitted from the light source unit 20 enters the optical fiber 16 from the end portion 162, is transmitted in the optical fiber 16, and then exits from the end portion 161 as the light exit point 121. The light exiting from the light exit point 121 is transformed into approximately parallel light (hereinafter referred to as parallel light) by the collimating lens 123 and then transmitted within the probe housing 120b. Specifically, the parallel light exiting from the collimating lens 123 passes through the optical element 124 and is reflected by the optical element 129 to enter the condenser lens 125.

[0140] Through the condenser lens 125, parallel light is transformed into light that converges near the mirror 113 and is reflected by the mirror 113. The light reflected by the mirror 113 passes through the condenser lens 125 again and becomes light that is close to parallel (hereinafter referred to as reflected light). The reflected light is transmitted within the probe housing 120b, passes through the optical element 124, and then enters the condenser lens 126 after being directed in a direction different from the incident direction. The reflected light is transformed into converging light by the condenser lens 126.

[0141] The converging light is separated into two lights, a first reflected light and a second reflected light, by the beam splitter 127. Here, a first pinhole of the light shielding member 128a and a second pinhole of the light shielding member 128b are arranged on the optical paths of the first reflected light and the second reflected light, respectively. The intensities of the light passing through the respective pinholes are measured by the photodetectors 31a and 31b placed after the first pinhole and the second pinhole, respectively.

[0142] The distance from the principal point of the condenser lens 126 to the first pinhole serving as the light incident point 122a is different from the distance from the principal point of the condenser lens 126 to the second pinhole serving as the light incident point 122b. The amount of light passing through the pinhole, that is, the amount of light incident on the light incident point, depends on the distance between the converging position of the condenser lens 126 and the position of the pinhole (i.e., the light incident point). Specifically, the closer the pinhole (i.e., the light incident point) is to the converging position of the condenser lens 126, the more light passes through.

[0143] The converging position of the condenser lens 126 depends on the relative position of the condenser lens 125 on the mirror 113 side and the mirror 113. Therefore, for example, the following control signal is sent from the control unit 14 to the drive mechanism 13. Here, the control signal is a signal that moves the movable part 12 in such a way that the intensity of the light measured by the photodetector 31a is always maintained at the maximum. Accordingly, by adjusting the position of the movable part 12, the relative position between the movable part 11 and the movable part 12 can be kept unchanged. Alternatively, the relative position of the movable part 12 can be adjusted by the control unit 14 via the drive mechanism 13 in such a way that the difference between the light intensity measured by the photodetector 31a and the light intensity measured by the photodetector 31b becomes zero.

[0144] [Regarding the effect]

[0145] Next, regarding the effect of the measuring device 1 according to the present embodiment, it will be described while comparing with the Figure 6 conventional optical probe 10x shown.

[0146] Specifically, in previous examples, light from a semiconductor laser 21x fixed to the movable part 12x was used to measure the relative position between the movable part 11x and the movable part 12x. However, in the measuring device 1, light emitted from the end 161 of the optical fiber 16 is used. The advantages of this configuration are described below.

[0147] The first advantage is the miniaturization and weight reduction of the movable part 12.

[0148] Generally, in order to suppress deterioration caused by air or the like, the semiconductor laser 21x is housed in a package having a metal casing and a glass window with a size of about a few millimeters. However, at the end 162 of the optical fiber 16 serving as the light emission point 121, a metal casing and a glass window are not required. Therefore, by making such an omission, the movable part 12 can be made lighter.

[0149] Regarding the size, as long as it is the optical fiber 16, the diameter of the end 161 can be made 1 mm or less. Therefore, the end 162 of the optical fiber 16 can be used as the light emission point 121 instead of the semiconductor laser 21x, and thus the size of the movable part 12 can be reduced.

[0150] Moreover, the optical fiber 16 has high symmetry and emits light from a small-diameter circular cross-section. Especially for a single-mode optical fiber, its cross-section is very small. For this reason, the optical fiber 16 can emit light with a unified spatial mode. Therefore, by using a small and lightweight lens with a short focal length as the collimating lens 123, the light emitted from the optical fiber 16 is converted into a collimated light beam with a small diameter, and beam divergence can also be suppressed.

[0151] If the diameter of the light can be reduced, each component such as a lens, a prism, and a mirror included in the optical system fixed to the movable part 12 can be made smaller. Therefore, the entire optical system can be miniaturized and lightened, which contributes to the miniaturization of the movable part 12.

[0152] In addition, the optical system included in the movable part 12 may also include a GRIN (Graded-Index) lens fixed to the end 161 of the optical fiber 16. By adopting a GRIN lens, the collimating lens 123 can be omitted, and thus the movable part 12 can be further miniaturized and lightened.

[0153] Light with a unified spatial mode can be focused into a smaller range. This means that a component with a small aperture can be used as the pinhole for detecting the relative position between the movable part 11 and the movable part 12. Or it means that the focal length of the lens for focusing light onto the pinhole can be reduced. Therefore, this also contributes to the miniaturization and weight reduction of the movable part 12.

[0154] However, the semiconductor laser 21x, which is a conventional light source, has spatial diffusivity and emits light asymmetrically in the vertical and horizontal directions. Therefore, divergence easily occurs in a collimated light beam with a small diameter, making it difficult to miniaturize an optical system such as a lens.

[0155] The second advantage is the reduction of wiring.

[0156] When operating the semiconductor laser 21x, different wires are required for the anode and cathode respectively to connect to the power supply. That is, at least two wires are needed to connect to the semiconductor laser 21x fixed to the movable part 12. Generally, if an output display installed inside the semiconductor laser 21x is also used, an additional wire is required. The more wires connected to the movable part 12, the more difficult it is to miniaturize the movable part 12.

[0157] In contrast, in the present embodiment, the light source unit 20 and the movable part 12 are provided separately. Only one optical fiber 16 for light emission needs to be connected to the movable part 12. Therefore, miniaturization of the movable part 12 can be achieved.

[0158] The third advantage is the reduction of heat generation.

[0159] In the semiconductor laser 21x, usually less than half of the consumed power is converted into light. The remaining power is released as heat. The heat discharged from the semiconductor laser 21x fixed to the movable part 12 causes a temperature rise inside the movable part 12. The temperature rise inside the movable part 12 causes a change in the refractive index of the air inside, that is, air turbulence occurs. Since the light L of the distance measuring mechanism for measuring the shape of the object to be measured also passes through the inside of the movable part 12, this turbulence has an adverse effect on the accuracy of measuring the shape of the object to be measured.

[0160] In contrast, in the present embodiment, the light source unit 20, which is the main heat source, is not provided in the movable part 12. The heat generated by the part fixed to the movable part 12 can be almost ignored in the optical fiber 16 connected to the movable part 12. Therefore, the influence of heat can be greatly reduced, and a decrease in the measurement accuracy of the object to be measured can be suppressed.

[0161] The fourth advantage is easy replacement.

[0162] Generally, the lifespan of the semiconductor laser 21x is about 10,000 hours. This lifespan is about one year when it is constantly lit. When the semiconductor laser 21x deteriorates, it becomes difficult to measure the relative position between the movable part 11 and the movable part 12, so the semiconductor laser 21x needs to be replaced.

[0163] When the semiconductor laser 21x is fixed to the movable part 12, optical system adjustment work for the optical system fixed to the movable part 12 needs to be carried out every time replacement is made. Since a part of the optical system in the movable part 12 is also shared in the interferometer 40 for measuring the shape of the object to be measured, careful attention is required during adjustment.

[0164] However, in the present embodiment, the laser element 21 and the movable part 12 are arranged separately. In this case, even if the laser element 21 needs to be replaced, only the adjustment of the optical system combined with the optical fiber 16 needs to be carried out. Therefore, the replacement adjustment work can be made easier.

[0165] (Embodiment 2)

[0166] Next, the measuring device according to Embodiment 2 will be described. The configuration of the measuring device according to the present embodiment is such that, instead of the photodetector provided in the movable part, the end of the optical fiber connected to the photodetector is connected to the movable part.

[0167] Hereinafter, Figure 2 will be used to describe the specific configuration of the measuring device according to the present embodiment. Figure 2 The schematic configuration of the measuring device according to the present embodiment is shown. In addition, the detailed description of the parts common to Embodiment 1 will be omitted or simplified, and hereinafter, the description will be centered on the differences from Embodiment 1.

[0168] The measuring device 2 according to the present embodiment, as Figure 2 shown, includes a probe 10, a drive mechanism 13, a control unit 14, a spring 15, and optical fibers 17 and 18. And the measuring device 2 includes a laser element 21, photodetectors 31a and 31b, and an interferometer 40.

[0169] [Probe]

[0170] The probe 10 includes a movable part 11 and a movable part 12. Since the configuration of the movable part 11 is the same as that in Embodiment 1, the description thereof will be omitted.

[0171] The movable part 12 includes a guiding mechanism 120a and a probe housing 120b. The configurations of the guiding mechanism 120a and the probe housing 120b are the same as those in Embodiment 1. In addition, the guiding mechanism 120a and the probe housing 120b can be appropriately changed in shape and size according to the elements provided in the movable part 12 or the connected cables, etc.

[0172] Moreover, the movable part 12 has a light emission point 121, and light incident points 122a and 122b. In the present embodiment, the specific configurations of the light emission point 121 and the light incident points 122a and 122b are different from those in the first embodiment. Specifically, the light emission point 121 is the light emission surface of the laser element 21. The light incident point 122a is the end 171 of the optical fiber 17. The light incident point 122b is the end 181 of the optical fiber 18.

[0173] The movable part 12 has an optical system fixed to the probe housing 120b. The optical system is the same as that in the first embodiment. Specifically, the optical system includes a collimating lens 123, an optical element 124, a condenser lens 125, a condenser lens 126, a beam splitter 127, and an optical element 129. In the present embodiment, the light shielding members 128a and 128b are not provided in the movable part 12.

[0174] [Optical fiber]

[0175] The optical fiber 17 is an example of a second optical fiber and has an end 171 and an end 172.

[0176] The end 171 is an example of a second end and is the light incident point 122a where the first reflected light is incident. The end 171 is directly or via other components fixed to the probe housing 120b.

[0177] The end 172 is the end on the side opposite to the end 171 of the optical fiber 17. The end 172 is not fixed to the probe housing 120b. The end 172 is connected to, for example, the light detector 31a. The end 172 emits the first reflected light to the light detector 31a, and the first reflected light is the light incident from the end 171 and transmitted in the optical fiber 17.

[0178] The optical fiber 18 is an example of a third optical fiber and has an end 181 and an end 182.

[0179] The end 181 is an example of a third end and is the light incident point 122b where the second reflected light is incident. The end 181 is directly or via other components fixed to the probe housing 120b.

[0180] The end 182 is the end on the side opposite to the end 181 of the optical fiber 18. The end 182 is not fixed to the probe housing 120b. The end 182 is connected to, for example, the light detector 31b. The end 182 emits the second reflected light to the light detector 31b, and the second reflected light is the light incident from the end 181 and transmitted in the optical fiber 18.

[0181] The optical fibers 17 and 18 can be single-mode optical fibers or multi-mode optical fibers, respectively. In order to obtain a sufficient amount of light, multi-mode optical fibers are advantageous.

[0182] Also, polarization maintaining optical fibers can be used for the optical fibers 17 and 18. By using polarization maintaining optical fibers, it becomes easier to separate the light used in the interferometer 40 from the light used for measuring the relative positions of the movable parts 11 and 12 by using polarization optical elements.

[0183] In the movable part 12, the end 171 of the optical fiber 17 is disposed on the optical path of the first reflected light separated by the beam splitter 127. Also, the end 181 of the optical fiber 18 is disposed on the optical path of the second reflected light separated by the beam splitter 127. Regarding the distance from the principal point of the condenser lens 126, the end 171 of the optical fiber 17 (light incident point 122a) is different from the end 181 of the optical fiber 18 (light incident point 122b).

[0184] [Laser element]

[0185] The laser element 21 is fixed to the movable part 12. The laser element 21 includes a light emission point 121. Specifically, the light emitting surface of the laser element 21 is the light emission point 121. The laser element 21 is, for example, a semiconductor laser.

[0186] [Optical detector]

[0187] The optical detector 31a is an example of a light intensity measurement unit that measures the intensity of the first reflected light incident on the light incident point 122a. The optical detector 31b is an example of a light intensity measurement unit that measures the intensity of the second reflected light incident on the light incident point 122b. The optical detectors 31a and 31b are, for example, photoelectric conversion elements such as photodiodes and phototransistors, respectively.

[0188] In the present embodiment, the optical detector 31a measures the intensity of the first reflected light that is incident from the end 171, transmitted through the optical fiber 17, and then emitted from the end 172. The optical detector 31a outputs a signal corresponding to the measured intensity to the control unit 14.

[0189] The optical detector 31b measures the intensity of the second reflected light that is incident from the end 181 and emitted from the end 182 after being transmitted through the optical fiber 18. The optical detector 31b outputs a signal corresponding to the measured intensity to the control unit 14.

[0190] [Control method for relative position between movable part 11 and movable part 12]

[0191] Next, a control method for the relative position between the movable part 11 and the movable part 12 will be described. Regarding the basic principle, since it is the same as that of the first embodiment, the description will focus on the differences.

[0192] The distance from the principal point of the condenser lens 126 to the end 171 of the optical fiber 17 is different from the distance from the principal point of the condenser lens 126 to the end 181 of the optical fiber 18. Regarding the amount of light incident from the end of the optical fiber into the interior of the optical fiber, the closer the end is to the condensing position of the condenser lens 126, the greater the amount of light. The condensing position of the condenser lens 126 depends on the relative position of the condenser lens 125 on the mirror 113 side and the mirror 113.

[0193] Therefore, for example, the control unit 14 sends the following signal to the drive mechanism 13, which is a signal for moving the movable part 12 in such a way that the intensity of the first reflected light measured by the photodetector 31a always becomes maximum. Accordingly, by adjusting the position of the movable part 12, the relative position of the movable part 11 and the movable part 12 can be kept unchanged. Alternatively, the relative position of the movable part 12 may be adjusted by the control unit 14 via the drive mechanism 13 in such a way that the difference between the light intensity measured by the photodetector 31a and the light intensity measured by the photodetector 31b becomes zero.

[0194] [Regarding the effects]

[0195] Next, while comparing with the Figure 6 conventional optical probe 10x shown, the effects of the measuring device 2 according to the present embodiment will be described.

[0196] Specifically, in the conventional example, the photodetectors 31ax and 31bx fixed to the movable part 12x are used to measure the relative position of the movable part 11x and the movable part 12x. In contrast, in the measuring device 2, the ends 171 of the optical fiber 17 and the ends 181 of the optical fiber 18 are used as the light incident points 122a and 122b, respectively, and the photodetectors 31a and 31b are arranged outside the movable part 12. Hereinafter, the advantages of such a configuration will be described.

[0197] The first advantage is the same as that of the first embodiment, which is the miniaturization of the movable part 12.

[0198] Similar to the case of the semiconductor laser 21x, in order to also seal the photodetectors 31ax and 31bx, a size of about several millimeters in diameter is required. In contrast, in the present embodiment, since the photodetectors 31a and 31b and the movable part 12 are arranged separately, the movable part 12 is connected to the ends 171 of the optical fiber 17 and the ends 181 of the optical fiber 18. Therefore, similar to the first embodiment, the movable part 12 can be made smaller and lighter. And in the present embodiment, the light-shielding member having a pinhole can be omitted. Therefore, further miniaturization and weight reduction can be achieved.

[0199] The second advantage is that wiring can be reduced. This is also the same as that of the first embodiment.

[0200] (Embodiment 3)

[0201] Next, the measuring device according to Embodiment 3 will be described. The measuring device according to this embodiment is different from the measuring devices according to Embodiments 1 and 2 in that neither a light detector nor a laser element is provided in the movable part. Specifically, in this embodiment, the light incident point and the light exit point are respectively the ends of the optical fiber.

[0202] The following uses Figure 3 to describe the specific configuration of the measuring device according to this embodiment. Figure 3 FIG. is a diagram showing a schematic configuration of the measuring device according to this embodiment. In addition, hereinafter, the detailed description of the parts common to Embodiment 1 or 2 will be omitted or simplified, and the description will be centered on the differences from Embodiment 1 or 2.

[0203] As Figure 3 shown, the measuring device 3 according to this embodiment is different from the measuring device 2 according to Embodiment 2 in that it includes an optical fiber 16 and a light source unit 20 instead of the laser element 21. The optical fiber 16 and the light source unit 20 are the same as the optical fiber 16 and the light source unit 20 included in the measuring device 1 according to Embodiment 1. That is, the measuring device 3 according to this embodiment has a configuration in which the Figure 1 shown measuring device 1 and the Figure 2 shown measuring device 2 are combined.

[0204] Specifically, in the measuring device 3, the light exit point 121 is the end 161 of the optical fiber 16. The light incident points 122a and 122b are the ends 171 of the optical fiber 17 and the end 181 of the optical fiber 18, respectively.

[0205] Accordingly, the laser element 21, the light detectors 31a and 31b, and the light shielding members 128a and 128b may not be provided in the movable part 12. It is also not necessary to route the power supply lines and signal lines connected to the laser element 21 and the light detectors 31a and 31b in the movable part 12. Therefore, compared with the conventional configuration, miniaturization and weight reduction can be more achieved. And the first to fourth advantages described in Embodiments 1 and 2 can be obtained.

[0206] (Embodiment 4)

[0207] Next, the measuring device according to Embodiment 4 will be described. In the measuring device according to this embodiment, an optical fiber bundle in which a plurality of cores are bundled together is connected to the movable part.

[0208] The following uses Figure 4 to describe the specific configuration of the measuring device according to this embodiment. Figure 4This is a diagram showing a schematic configuration of the measuring device according to the present embodiment. In addition, hereinafter, the detailed description of the parts common to the embodiments will be omitted or simplified, and the description will be centered on the differences from Embodiment 1 or 2.

[0209] As shown in Figure 4 , the measuring device 4 according to the present embodiment includes a probe 10, a drive mechanism 13, a control unit 14, a spring 15, and an optical fiber bundle 19. Further, the measuring device 4 includes a laser element 21, photodetectors 31a and 31b, and an interferometer 40. In addition, similar to Embodiment 1 or 3, the measuring device 4 may include an optical fiber 16 and a light source unit 20 instead of the laser element 21.

[0210] [Probe]

[0211] The probe 10 includes a movable part 11 and a movable part 12. Since the configuration of the movable part 11 is the same as that of Embodiment 1, the description thereof will be omitted.

[0212] The movable part 12 includes a guiding mechanism 120a and a probe housing 120b. The configurations of the guiding mechanism 120a and the probe housing 120b are the same as those of Embodiment 1. In addition, the guiding mechanism 120a and the probe housing 120b can be appropriately changed in shape and size according to the elements provided in the movable part 12 or the connected cables.

[0213] Further, the movable part 12 has a light emission point 121 and a light incidence point 122. The light emission point 121 is the light emission surface of the laser element 21, similar to Embodiment 2. In the present embodiment, the specific configuration of the light incidence point 122 is different from that of Embodiment 2. Specifically, the light incidence point 122 is the end portion 191 of the optical fiber bundle 19.

[0214] The movable part 12 has an optical system fixed to the probe housing 120b. The difference between the optical system and that in Embodiment 1 is that it does not include a beam splitter 127. Specifically, the optical system includes a collimating lens 123, an optical element 124, a condenser lens 125, a condenser lens 126, and an optical element 129.

[0215] [Optical Fiber Bundle]

[0216] The optical fiber bundle 19 is an example of an optical fiber and is a multi-core optical fiber including a plurality of cores. Each core of the optical fiber bundle 19 can transmit different lights.

[0217] Figure 5 This is a diagram showing the concept of the optical fiber bundle. Figure 5The optical fiber bundle 19 shown includes seven cores 19A, 19B, 19C, 19D, 19E, 19F, and 19G. Additionally, the number of cores is only required to be multiple, without any special limitation. For example, one end of the optical fiber bundle 19 has multiple cores bundled together, and at least one of the multiple cores is separated at the other end. The end in the state where the multiple cores are bundled together can arrange the cores in a narrow space area. At the end in the state where the multiple cores are separated, an independent optical detector can be connected to each core. Or multiple ends can be gathered and connected to one optical detector.

[0218] In the present embodiment, the end 191 in the state where the multiple cores of the optical fiber bundle 19 are bundled together is fixed near the focal point of the condenser lens 126 of the probe housing 120b as Figure 4 shown.

[0219] The end in the state where the cores of the optical fiber bundle 19 are separated is not fixed to the movable part 12 but is connected to an optical detector. Instead of connecting an independent optical detector to all the cores, one optical detector can be connected to multiple cores. For example, at the end 191 where the seven cores 19A, 19B, 19C, 19D, 19E, 19F, and 19G are bundled together, the other end corresponding to the core 19A located at the center is connected to the optical detector 31a. The ends corresponding to the cores 19B, 19C, 19D, 19E, 19F, and 19G located around the core 19A are connected to the optical detector 31b.

[0220] [Optical Detector]

[0221] In the present embodiment, at least two optical detectors are provided. Specifically, as Figure 4 shown, the optical detectors 31a and 31b respectively measure the intensity of light transmitted by different cores of the optical fiber bundle 19. More specifically, the optical detector 31a measures the intensity of the reflected light incident on the core 19A located at the center of the end 191 of the optical fiber bundle 19. The optical detector 31b measures the total intensity of the reflected light incident on each of the six cores 19B, 19C, 19D, 19E, 19F, and 19G located around the end 191 of the optical fiber bundle 19.

[0222] [Control Method for the Relative Position of the Movable Part 11 and the Movable Part 12]

[0223] Next, a method for controlling the relative position of the movable part 11 and the movable part 12 will be described.

[0224] The cross-sectional distribution of the light intensity generated by the condenser lens 126 in the plane where the end portion 191 of the optical fiber bundle 19 is located will vary depending on the focusing position of the condenser lens 126. Specifically, the closer to the focusing position of the condenser lens 126, the more the light intensity is concentrated toward the central portion and attenuated in the peripheral portion. The focusing position of the condenser lens 126 depends on the relative position between the condenser lens 125 on the mirror 113 side and the mirror 113.

[0225] Therefore, at the end portion 191 of the optical fiber bundle 19, by comparing the light intensity incident on the core 19A in the central portion with the light intensity incident on at least one of the cores 19B, 19C, 19D, 19E, 19F, and 19G in the peripheral portion, it is possible to know to what extent the focusing position approaches the end portion 191 of the optical fiber bundle 19.

[0226] For example, by controlling the drive mechanism 13, when the position of the movable portion 12 is slightly deviated, if the light intensity ratio of the light incident on the core 19A in the central portion to the light intensity incident on the cores 19B, 19C, 19D, 19E, 19F, and 19G in the peripheral portion increases, it can be known that the focusing position is close to the end portion 191 of the optical fiber bundle 19. On the contrary, if the light intensity ratio decreases, it can be known that the focusing position has moved away from the end portion 191 of the optical fiber bundle 19.

[0227] The position where the condenser lens 126 focuses most depends on the relative position between the movable portion 11 and the movable portion 12. Therefore, by knowing the ratio of the light amounts incident on the respective cores, the control unit 14 can calculate the relative position between the movable portion 11 and the movable portion 12. The control unit 14 calculates the moving direction and moving distance of the movable portion 12 so that the calculated relative position approaches a specified value. Then, by sending a control signal to the drive mechanism 13, the control unit 14 can adjust the position of the movable portion 12 through the drive mechanism 13.

[0228] The advantage of this embodiment is that the end of the optical fiber to be fixed to the movable portion 12 is one. Therefore, it is possible to make the movable portion 12 smaller and lighter. In addition, in a configuration where a plurality of cores are present in the peripheral portion, as long as each core is connected to an independent light detector, information on the tilt of the mirror 113 can be obtained.

[0229] In addition, in the measuring device 4 according to this embodiment, in the same manner as in Embodiment 1 or 3, a light source unit 20 and an optical fiber 16 can be provided instead of the laser element 21. Accordingly, the first to fourth advantages described in Embodiment 1 can be obtained.

[0230] Also, the optical fiber bundle 19 can also be used as an optical fiber for light emission into the movable part 12. For example, the central core 19A is not only used for the transmission of reflected light, but can also be used for the transmission of light from the laser element 21. In this case, the end 191 of the optical fiber bundle 19 is the light emission point 121 and also becomes the light incident point 122. That is to say, the light emission point 121 can be the same as the light incident point 122.

[0231] In this case, an optical element such as an optical circulator for controlling the traveling direction of light is connected to the end on the side opposite to the end 191 of the central core 19A. Accordingly, the light from the laser element 21 can be made to enter the core 19A and exit from the end 191, and at the same time, the reflected light incident from the end 191 can be made to travel in the core 19A and then be directed toward the photodetector 31a.

[0232] (Other embodiments)

[0233] The measuring device related to one or more embodiments has been described above based on the embodiments, but the present disclosure is not limited to these embodiments. Within the scope not departing from the gist of the present disclosure, the forms obtained by performing various modifications conceivable by those skilled in the art on these embodiments, and the forms constructed by combining the constituent elements in different embodiments are all included in the scope of the present disclosure.

[0234] For example, in the measuring device related to each embodiment, the movable part 11 and the movable part 12 may not be connected at all. The weight of the movable part 11 can be utilized to change the relative position of the movable part 11 and the movable part 12 in the vertical direction. In this case, by adjusting the posture of the measuring device to make the vertical direction coincide with the plumb direction, the weight of the movable part 11 can be effectively utilized. In addition, in order not to separate the movable part 11 from the movable part 12, a restricting part such as a protrusion for restricting the position of the movable part 11 can be provided.

[0235] Moreover, the present disclosure can be implemented as a control system or a control method for a movable body included in a measuring device. The control system is realized by, for example, one or more computer devices. Specifically, the control system includes a control unit that controls a drive mechanism, and the drive mechanism adjusts the position of a second movable body having a light emission point, a light incident point, and an optical system. The light emission point or the light incident point is the end of at least one optical fiber. The light emitted from the light emission point is irradiated onto a reflector provided on a first movable body via the optical system, and the reflected light reflected from the reflector enters the light incident point. The control unit controls the drive mechanism based on the intensity of the reflected light incident on the light incident point, and thereby adjusts the position of the second movable body.

[0236] Also, the present disclosure can be implemented as a non-contact measurement device. Specifically, when measuring a measurement object, the first movable body of the measurement device can be configured not to contact the measurement object. For example, an interferometer can be configured to irradiate light onto the surface of the measurement object and receive the reflected light of the light from the measurement object.

[0237] In addition, one or more computer devices include, for example, a non-volatile memory storing a program, a volatile memory which is a temporary storage area for executing the program, an input / output port, a processor for executing the program, and the like. And the control system can be a programmable FPGA (Field Programmable Gate Array), or a reconfigurable processor in which the connection and setting of circuit units in an LSI are reconfigurable. The functions executed by the control system can be implemented by software or by hardware.

[0238] Moreover, the control method of the movable body included in the measurement device includes a step of controlling a drive mechanism that adjusts the position of a second movable body having a light emission point, a light incidence point, and an optical system. The light emission point or the light incidence point is the end of at least one optical fiber. The light emitted from the light emission point is irradiated onto a reflector included in the first movable body via the optical system, and the reflected light reflected from the reflector is incident on the light incidence point. In the step of performing control, the position of the second movable body is adjusted by controlling the drive mechanism according to the intensity of the reflected light incident on the light incidence point.

[0239] Also, the present disclosure can be implemented as a program that causes a computer to execute the control method of the movable body included in the measurement device. And the present disclosure can be implemented as a non-transitory recording medium storing the program.

[0240] Furthermore, the above-described embodiments can be variously changed, replaced, added, omitted, etc. within the scope of the claims or equivalents thereof.

[0241] Industrial Applicability

[0242] The present disclosure can be used in various measurement devices such as inspection of industrial products that require high-precision distance measurement.

Claims

1. A measuring device, The measuring device comprises: a first movable body having a reflector; A second movable body, the second movable body having a light exit point, a light incident point and an optical system; A driving mechanism for adjusting the position of the second movable body; A control unit, for controlling the driving mechanism; as well as at least one optical fiber, The light emitted from the light emission point is irradiated to the reflector via the optical system. The reflected light reflected from the reflector is incident on the light incident point, The control unit controls the driving mechanism according to the intensity of the reflected light incident on the light incident point, thereby adjusting the position of the second movable body. The light exit point or the light entrance point is an end of the at least one optical fiber.

2. The measuring device according to claim 1, When measuring an object, the first movable body comes into contact with the object.

3. The measuring device according to claim 1, The measuring device includes an elastic body that couples the first movable body and the second movable body.

4. The measuring device according to any one of claims 1 to 3, The at least one optical fiber comprises a first optical fiber, The light exit point is the first end of the first optical fiber, The second movable body has: a beam splitter, for separating the reflected light into a first reflected light and a second reflected light; A first light shielding member having a first pinhole for the first reflected light to be incident on; and The second light shielding member has a second pinhole for the second reflected light to be incident on, The second movable body has a plurality of light incident points. The first pinhole and the second pinhole are each the light incident point.

5. The measuring device according to any one of claims 1 to 3, The second movable body has: A laser element including said light exit point; as well as a beam splitter, which separates the reflected light into a first reflected light and a second reflected light, The at least one optical fiber comprises: a second optical fiber having a second end portion for incident upon the first reflected light; as well as a third optical fiber having a third end portion for the second reflected light to be incident on, The second movable body has a plurality of light incident points. The second end and the third end are each the light incident point.

6. The measuring device according to any one of claims 1 to 3, The second movable body has a beam splitter for separating the reflected light into a first reflected light and a second reflected light. The at least one optical fiber comprises: First optical fiber; a second optical fiber having a second end portion for incident upon the first reflected light; as well as a third optical fiber having a third end portion for the second reflected light to be incident on, The light exit point is the first end of the first optical fiber, The second movable body has a plurality of light incident points. The second end and the third end are each the light incident point.

7. The measuring device according to any one of claims 1 to 3, The at least one optical fiber comprises a multi-core optical fiber, the multi-core optical fiber comprising a plurality of cores, The second movable body has a plurality of light incident points. The ends of each of the plurality of cores are the light incident points.

8. The measuring device according to any one of claims 1 to 3, The at least one optical fiber is a single mode optical fiber.

9. The measuring device according to any one of claims 1 to 3, The at least one optical fiber is a multimode optical fiber.

10. The measuring device according to any one of claims 1 to 3, The optical system includes a gradient index lens secured to an end of the at least one optical fiber.

11. The measuring device according to any one of claims 1 to 3, The at least one optical fiber comprises a multi-core optical fiber, the multi-core optical fiber comprising a plurality of cores, An end of one of the plurality of cores is the light incident point and the light exit point.

12. The measuring device according to claim 4, The measuring device comprises a laser element, The light emitted from the laser element enters the first optical fiber from an end portion on the opposite side to the first end portion, propagates through the first optical fiber, and is emitted from the first end portion.

13. The measuring device according to any one of claims 1 to 3, The measuring device includes a light intensity measuring unit that measures the intensity of reflected light incident on the light incident point.

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